Wing-to-body fairing with spray-on foam and noise reduction method

ABSTRACT

A fairing includes a fairing body having a fairing interior and an interior surface and a spray-on insulation foam layer provided on the interior surface of the fairing body.

TECHNICAL FIELD

The disclosure generally relates to wing to body fairings in aircraft.More particularly, the disclosure relates to a wing to body fairing withfoam which reduces vibration, fatigue and cabin noise in an aircraft anda method of reducing cabin noise or reducing panel vibration in anaircraft.

BACKGROUND

In modern commercial aircraft, heavy insulation blankets may be placedon wing to body fairings to reduce cabin noise to acceptable levels byClamping vibration of the wing to body fairing panels. However,insulation blankets may contribute excessive weight to the fairings.Moreover, insulation blankets may not be effective in Clamping vibrationof the fairing panels during operation of the aircraft.

Therefore, a wing to body fairing with foam which reduces vibration,fatigue and cabin noise in an aircraft and a method of reducing cabinnoise or reducing panel vibration in an aircraft are needed.

SUMMARY

The disclosure is generally directed to a fairing with spray-on foam,which reduces vibration, fatigue and cabin noise in an aircraft. Anillustrative embodiment of the fairing includes a fairing body having afairing interior and an interior surface and an insulating foam layerprovided on the interior surface of the fairing body.

The disclosure is further generally directed to a method of reducingcabin noise or reducing panel vibration in an aircraft. An illustrativeembodiment of the method includes providing a fairing having a fairingbody with an interior surface, providing an insulating foam, applyingthe spray-on insulation foam to the interior surface of the fairing bodyand installing the fairing on an aircraft.

In some embodiments, the method of reducing cabin noise or reducingpanel vibration in an aircraft may include providing a fairing having afairing body including a plurality of fairing panels with an interiorsurface; providing a spray-on insulation foam; spraying the spray-oninsulation foam on the interior surface of the fairing body; andinstalling the fairing on an aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom perspective view of an illustrative embodiment of awing to body fairing with spray-on foam.

FIG. 1A is a cross-sectional view of a portion of a fairing panel of thewing to body fairing, with a spray-on foam layer provided on an interiorpanel surface of the fairing panel.

FIG. 2 is a perspective view of a portion of a fairing panel of the wingto body fairing, with a spray-on foam layer deposited on the fairingpanel.

FIG. 2A is a cross-sectional view of a portion of a fairing panel of thewing to body fairing, with insulation pins extending from the interiorpanel surface and a spray-on foam layer provided on the insulation pinsand the interior panel surface of the fairing panel.

FIG. 3 is a flow diagram of an illustrative embodiment of a method ofreducing cabin noise or reducing panel vibration in an aircraft.

FIG. 4 is a flow diagram of an aircraft production and servicemethodology.

FIG. 5 is a block diagram of an aircraft.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the described embodiments or the application anduses of the described embodiments. As used herein, the word “exemplary”or “illustrative” means “serving as an example, instance, orillustration.” Any implementation described herein as “exemplary” or“illustrative” is not necessarily to be construed as preferred oradvantageous over other implementations. All of the implementationsdescribed below are exemplary implementations provided to enable personsskilled in the art to practice the disclosure and are not intended tolimit the scope of the appended claims. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary or thefollowing detailed description.

Referring initially to FIGS. 1-2A, an illustrative embodiment of thewing to body fairing with foam, hereinafter fairing, is generallyindicated by reference numeral 1. In some embodiments, the fairing 1 maybe a wing to body fairing (WTBF) of a commercial aircraft, for exampleand without limitation. The fairing 1 may include a fairing body 1 ahaving a fairing interior 5. In some embodiments, the fairing body 1 amay have multiple fairing panels 2 which are assembled into the fairingbody 1 a according to the knowledge of those skilled in the art. Eachfairing panel 2 may have an exterior panel surface 3 which generallyfaces away from the fairing interior 5 of the fairing body 1 a and aninterior panel surface 4 which generally faces the fairing interior 5 ofthe fairing body 1 a. The fairing body 1 a may have a fairing edge 6.

Referring to FIG. 1 a, at least one insulation foam layer 8 may besprayed on the interior panel surfaces 4 of the fairing panels 2 of thefairing body 1 a. In some embodiments, the insulation foam layer 8 maybe closed cell polyurethane spray-on insulation foam which is sprayedonto the interior panel surfaces 4 of the fairing panels 2. Apolyurethane foam which is suitable for the spray-on insulation foamlayer 8 is TIGER FOAM® which can be obtained from Commercial ThermalSolutions, Inc. of Spring Lake, N.J. (www.tigerfoam.com). In someembodiments, the insulation foam layer 8 may be applied to the interiorpanel surfaces 4 of the fairing panels 2 using an alternativeapplication method. For example and without limitation, the insulationfoam layer 8 may be a prepared foam layer which is applied to theinterior panel surfaces 4 using adhesive and pressure. The insulationfoam layer 8 may be contiguously applied to the interior panel surfaces4 of the fairing panels 2. Therefore, the insulation foam layer 8 may becontinuous generally throughout the entire surface area which isrepresented by the interior panel surfaces 4 of the fairing panels 2.

As shown in FIG. 1A, in some embodiments the insulation foam layer 8 mayhave a core foam portion 9. A tapered foam portion 10 may extendoutwardly from the edges of the core foam portion 9 toward the fairingedge 6 of the fairing body 1 a. Taper is used to control weight andenhance handling durability. Edges are not so important relative tocenter portion for foam benefit. A fairing flange 2 a may extend betweenthe tapered foam portion 10 and the fairing edge 6. The fairing flange 2a may facilitate attachment of the fairing body 1 a to the structuralelements (not shown) of an aircraft (not shown) according to theknowledge of those skilled in the art. The insulation foam layer 8 maybe omitted from the fairing flange 2 a. The insulation foam layer 8,which is a closed cell polyurethane foam, may have a density of about1.75 lb/ft³, or a density in the range between about 1.50 and about 2.0lb/ft³. In some embodiments, the core foam portion 9 of the insulationfoam layer 8 may have a thickness of about 2 inches. The thickness ofthe tapered foam portion 10 may decrease from about 2 inches to 0 inchesfrom the core foam portion 9 to the fairing flange 2 a. The main featureis to eliminate corners that may interfere with the handling of thepanel(s). Spray on foam insulation is typically not uniform in thicknessupon application. Secondary machining to a specific thickness dimensionis typically needed. In one embodiment the spray on foam may not bemachined and the resulting thickness may range from 0.5 to 3 inches.

As shown in FIG. 2A, in some applications insulation pins 12 may beinstalled on the interior panel surface 4 of each fairing panel 2. Theinsulation pins 12 may ensure that the insulation foam layer 8 remainson each fairing panel 2 throughout the service life of the fairingpanels 2 while also ensuring the transfer of vibration energy From panelto foam.

After the insulation foam layer 8 is applied to the interior panelsurfaces 4 of the fairing panels 2, the fairing 1 may be installed on acommercial aircraft (not shown) according to the knowledge of thoseskilled in the art. During operation of the aircraft, the insulationfoam layer 8 may reduce wing-to-body fairing vibration, fatigue andcabin noise by dissipating energy via a Clamping and mass effect.

Referring next to FIG. 3, a flow diagram 300 of an illustrativeembodiment of a method of reducing cabin noise or reducing panelvibration in an aircraft is shown. In block 302, a foam may be provided.In some embodiments, the foam may be a closed cell polyurethane spray-oninsulation foam, for example and without limitation. A polyurethane foamwhich is suitable for the spray-on foam layer is TIGER FOAM® which canbe obtained from Commercial Thermal Solutions, Inc. of Spring Lake, N.J.(www.tigerfoam.com). In some embodiments, the foam may be a preparedfoam layer. In block 304, a wing to body fairing having wing to bodyfairing panels may be provided. In block 306, the foam may be applied tothe interior surfaces of the wing to body panels of the fairing byspraying or by application using adhesive and pressure to form aninsulation foam layer on the interior surfaces of the wing to bodypanels. In some embodiments, the insulation foam layer may have a corefoam portion and a tapered foam portion which extends from the edges ofthe core foam portion. In block 308, the fairing may be installed on anaircraft. During operation of the aircraft, the insulation foam layermay reduce wing-to-body fairing vibration, fatigue and cabin noise bydissipating energy via a damping effect.

In block 304 a, in some embodiments insulation pins may be provided. Inblock 304 b, the insulation pins may be installed on the interiorsurfaces of the wing body panels of the fairing prior to application ofthe foam on the interior surfaces of the wing to body fairing panels inblock 306. The insulation pins may ensure that the insulation foam layerremains on each fairing panel throughout the service life of the fairingpanels.

Referring next to FIGS. 4 and 5, embodiments of the disclosure may beused in the context of an aircraft manufacturing and service method 78as shown in FIG. 4 and an aircraft 94 as shown in FIG. 5. Duringpre-production, exemplary method 78 may include specification and design80 of the aircraft 94 and material procurement 82. During production,component and subassembly manufacturing 84 and system integration 86 ofthe aircraft 94 takes place. Thereafter, the aircraft 94 may go throughcertification and delivery 88 in order to be placed in service 90. Whilein service by a customer, the aircraft 94 may be scheduled for routinemaintenance and service 92 (which may also include modification,reconfiguration, refurbishment, and so on).

Each of the processes of method 78 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof vendors, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

A further embodiment of method 78 may include receiving an assembledaircraft having fairing. The aircraft may further include a wing to bodyfaring. The aircraft may further have a wing to body fairing wherelocated aft of a wheel well. The aircraft may further have a wing tobody fairing where located aft of a wheel well where the wheel wellinclude a opening that exposes the interior of the wheel well to theexterior of the aircraft. The method may include removing a panel of thefaring and applying a foam insulation to an interior surface of thepanel. The method may further include machining the foam to a desiredthickness and shape. The method may further include a spraying on a foaminsulation material that bonds to the surface of the panel.

As shown in FIG. 5, the aircraft 94 produced by exemplary method 78 mayinclude an airframe 98 with a plurality of systems 96 and an interior100. Examples of high-level systems 96 include one or more of apropulsion system 102, an electrical system 104, a hydraulic system 106,and an environmental system 108. Any number of other systems may beincluded. Although an aerospace example is shown, the principles of theinvention may be applied to other industries, such as the automotiveindustry.

The apparatus embodied herein may be employed during any one or more ofthe stages of the production and service method 78. For example,components or subassemblies corresponding to production process 84 maybe fabricated or manufactured in a manner similar to components orsubassemblies produced while the aircraft 94 is in service. Also one ormore apparatus embodiments may be utilized during the production stages84 and 86, for example, by substantially expediting assembly of orreducing the cost of an aircraft 94. Similarly, one or more apparatusembodiments may be utilized while the aircraft 94 is in service, forexample and without limitation, to maintenance and service 92.

Although the embodiments of this disclosure have been described withrespect to certain exemplary embodiments, it is to be understood thatthe specific embodiments are for purposes of illustration and notlimitation, as other variations will occur to those of skill in the art.

1. A fairing, comprising: a fairing body having a fairing interior andan interior surface; and an insulation foam layer provided on saidinterior surface of said fairing body.
 2. The fairing of claim 1 whereinsaid fairing body comprises a plurality of fairing panels each having aninterior panel surface, and wherein said insulation foam layer isprovided on said interior panel surface of said plurality of fairingpanels.
 3. The fairing of claim 1 wherein said insulation foam layercomprises a closed cell polyurethane foam layer.
 4. The fairing of claim1 wherein said fairing body comprises a wing to body fairing.
 5. Thefairing of claim 1 wherein said insulation foam layer comprises a corefoam portion and a tapered foam portion extending from said core foamportion.
 6. The fairing of claim 5 wherein said core foam portion has athickness of about 2 inches.
 7. The fairing of claim 6 wherein saidtapered foam portion has a thickness of about 0 inches to about 2inches.
 8. The fairing of claim 5 further comprising a fairing flangehaving a fairing edge extending from said fairing body and wherein saidspray-on insulation foam layer is omitted from said fairing flange fromsaid tapered foam portion to said fairing edge.
 9. A method of reducingcabin noise in an aircraft, comprising: providing a fairing having afairing body with an interior surface; applying an insulation foam tothe interior surface of the fairing body; and method further comprisingremoving said fairing from an assembled aircraft.
 10. The method ofclaim 9 further comprising installing said fairing having the appliedinsulation foam on said aircraft.
 11. The method of claim 9 wherein saidproviding insulation foam comprises providing a spray-on polyurethaneinsulation foam.
 12. The method of claim 11 wherein said providing aspray-on polyurethane insulation foam comprises providing a closed-cellspray-on polyurethane insulation foam.
 13. The method of claim 9 whereinsaid applying said insulation foam to said interior surface of saidfairing body comprises spraying a spray-on insulation foam layer havinga core foam portion and a tapered foam portion extending from said corefoam portion on said interior surface of said fairing body.
 14. Themethod of claim 13 wherein said spraying a spray-on insulation foamlayer having a core foam portion and a tapered foam portion extendingfrom said core foam portion on said interior surface of said fairingbody comprises spraying a spray-on insulation foam layer having a corefoam portion with a thickness of about 2 inches and a tapered foamportion extending from said core foam portion with a thickness of about0 inches to about 2 inches on said interior surface of said fairingbody.
 15. The method of claim 14 wherein said providing a fairing havinga fairing body with an interior surface comprises providing a fairinghaving a fairing body and a fairing flange having a fairing edgeextending from said fairing body and wherein said spraying said spray-oninsulation foam on said interior surface of said fairing body comprisesomitting said spray-on insulation foam from said fairing flange fromsaid tapered foam portion to said fairing edge.
 16. A method of reducingcabin noise in an aircraft, comprising: providing a fairing having afairing body including a plurality of fairing panels with an interiorsurface; providing a spray-on insulation foam; spraying said spray-oninsulation foam on said interior surface of said fairing body; andinstalling said fairing on an aircraft.
 17. The method of claim 16wherein said providing a spray-on insulation foam comprises providing aspray-on polyurethane insulation foam.
 18. The method of claim 17wherein said providing a spray-on polyurethane insulation foam comprisesproviding a closed-cell spray-on polyurethane insulation foam.
 19. Themethod of claim 16 wherein said spraying said spray-on insulation foamon said interior surface of said fairing body comprises spraying aspray-on insulation foam layer having a core foam portion and a taperedfoam portion extending from said core foam portion on said interiorsurface of said fairing body.
 20. The method of claim 19 wherein saidspraying a spray-on insulation foam layer having a core foam portion anda tapered foam portion extending from said core foam portion on saidinterior surface of said fairing body comprises spraying a spray-oninsulation foam layer having a core foam portion with a thickness ofabout 2 inches and a tapered foam portion extending from said core foamportion with a thickness of about 0 inches to about 2 inches on saidinterior surface of said fairing body.
 21. The method of claim 20wherein said providing a fairing having a fairing body with an interiorsurface comprises providing a fairing having a fairing body and afairing flange having a fairing edge extending from said fairing bodyand wherein said spraying said spray-on insulation foam on said interiorsurface of said fairing body comprises omitting said spray-on insulationfoam from said fairing flange from said tapered foam portion to saidfairing edge.